Feeding motor for rock drills



1941- w. A. SMITH, JR

FEEDING MOTOR FOR ROCK DRILLS 2 Sheets-Sheet 1 Filed Nov. 27, 1939 ATTORNEY Oct. 7, 1941. w. A. SMITH, JR

" FEEDING MOTOR FOR ROCK DRILLS Filed Nov. 27,. 1959 2 Sheets-Sheet 2 INVENTOR W/LL/AM A. sM/n/ J2 ATTORNEY Patented Oct. 7, 1941 UNITED STATES PATENT OFFICE! v i 2,257,ss9

FEEDING MOTOR FOR noon DRILLS William A. Smith, Jr., Cleveland, Ohio, assignor to The Cleveland Rock Drill Oompany. land, Ohio, a. corporation of Ohio Cleve- Application November 27, 1939, Serial No. 306,246

This invention relates broadly to rock drills, but more particularly to a feeding mechanism for rock drills of the drifter type.

One bject of this invention is to provide a rock drill with a power actuated feeding mechanismcapable of imparting feeding motion to the drill in two directions.

Another object of this invention is to provide such feeding mechanism with valve means for automatically shutting off the feeding motor when the rock drill reaches theend of its feeding movement in at least one direction.

Other Objects more Or less ancillary tothe foregoing reside in'the specific construction and aggroupment of the elements peculiar to this structure, as will'become apparent from. a more com- 'pleteexamination of this specification. In the drawings:

Fig; 1 is aside elevational view, partly in section, of a rock, drill assemblyembodying the invention.

Fig. 2 is .an enlarged longitudinal sectional view of'the feeding motor shown in Fig. 1.

Fig,- 3 is an enlarged cross sectional View taken v in a plane indicated byline 3-4 in Fig. 2.

Figs. 4. and 5 are views similar to Fig. 3' illustrating the throttle valve in different positions.

Fig. 6 isan end view of. the feedin motor looking inthe direction of the arrows 6-6, in Fig. 1;.

" ,Fig. '7 is a perspective view of the coupling member shown in Fig. 2.

* Fig. 8 is an enlarged cross sectional'view taken in a plane indicated by line 88 in Fig. 2.

Figs; 9v and 10 are views similar to Fig. 8 illustrating the. throttle valve in diiferent positions.

Fig. 11 is a cross sectional view taken in a plane indicated by line shown in Fig. 2.

Fig. 12 is a cross sectional view taken in a plane indicated by line |2f| 2 in Fig. 2.

Fig. 13 is a cross sectional viewtaken in a plane indicated in line |3|3 in Fig. 2.

Fig. 14 is a cross sectional view taken in a plane indicated in line |4|4 in Fig. 2. I Fig..l5 is a cross sectional view taken in a plane indicated in line |5--|5 in Fig. 2.

' Referring to the drawings, 2|] represents the rock drill assembly including the cylinder 2| hav: ing reciprocably mounted therein a piston (not shown) capable of delivering impacts to a drill steel 22 slidably mounted within "a front end 23.

On the other end of the cylinder 2|, there is mounted aback head 24 held in place by the usual side bolts 25. extending through the cylinder and partly through the front head 23. The rock drill is slidably mounted on" a support or shell 25 of substantially U-shaped cross section and probinding or Otherwise incre shell 26, withinwhich boss is mounted'a feed nut 29'held in place by' -a retaining nut 30-. Through the feed nut "29 extends a rotatable feed screw 3| having its left end in Fig. 1, hereinafter referred 'to as the front end, journaled within a bearing 32 secured to the front end of the shell by one or morebolts 33. The rear end of the shell 26 includes a feed motor housing 34 having its front end closed by a cap 35 and its rear end by a cover 36, the cap 34 being an integral part of the'shell 26 while the housing 34' and cover 36 are secured thereto by bolts 31'. The rear end of the screw 3| is located in the cap 35 where it is terminated by a head 38 rotatably mounted Within a bushing 39 pressed in the front end portion of the cap 35. In the cap 35, there is alsothe shank 40 of an internal ringfgear 4|, which shank is journaled within a stationary spacer 40 and isoperatively connected to the head 38 of the feed screw 3| by an 'Oldham coupling 42', thereby permitting slight misalignment of the'screw relative to 'the shankwithout a'singthe frictional resistance to rotation; I

Located in the interior of the'ring gear 4|; there is the front end portion of a rotor-shaft 43,'which portion is shaped to form a pinion 44 meshing with three equally spaced gear wheels 45 rotatably mounted on stationary shafts 46 carried'by' a spider 41 secured to-tlie cap 35 by a dowel pin 48. The gear wheels 45 are also in operative engagement with the internal "gear ll for transmitting rotation thereto from the pinion at a greatlyreduced rate of speed. The shaft 43 is journaled within two needle bearings 49 and ||l3 operatively carried by two longitudinally spaced end plates 50 and 5| respectively, which end plates are also'secured to the cap- 35"by the.

dowel pin 48. Clamped between the'plates 50 and 5|, there is a stator 52 also held against rotation by the dowel pin 48. on its peripheral wall, the-stator 52 is provided with a partly circular groove 53 while'its interior is shaped to form a rotor chamber 54 of substantially oval shaped'cross'section within which is rotatably.

. mounted a cylindrical rotor 55 secured on the vided with the usual, conelike member 21' depending therefrom for attachment of the shell on any suitable support. Depending from the cylinder 2|,there is a boss 28 slidable within the shaft 43 by a key- 56. The rotor closely fits within the chamber 54 at two diametrically opposed places 51 and 58 from which the chamber 54 extends laterally on both sides thereof to form two crescentlike compartments 59; and 60 having their longitudinal ends'closed by the plates 50 and 5|. The rotor is formed with-a plurality of equallyQspaced' longitudinally extending grooves 6| accommodating radiallymovable vanes '62 capable of fluid tight engagement with the inneryvall of the rotor'chamber'55, each groove '6 hasits bottom wall formed with a small recess s3yextending the full length thereof and consequently openingthroughthe side walls of the tion may be imparted to the valve. The bore 64 is closed at its lower end by a plug 61 on which rests a compression spring 88 active on the throttle valve 65 for maintaining it in its uppermost position within the bore 64. Adjacent the handle 66, the throttle valve 65 within the bore 64 is provided with a serrated1head69, the serrations of which are engageable by a spring pressed plunger (not shown) for preventing accidental rotation of the throttle valve. The cover 36 is also formed with a-boss 19 having adequately mounted therein a motive fluid connection II for admitting motive fluid into the bore 84 through a passage 12. The valve 65 is provided with a central bore I3 and, in the vertical plane indicated by line 33 in Fig. 2, with a radial port I4 opening into the bore I3, and with a semicircular groove I5 capable of communication with an exhaust port 16 provided through the wall of the cover 35. In the vertical plane indicated by line 8-8 in Fig. 2, the throttle valve is provided with another radial port TI opening into the bore 13, and with a semicircular groove I8 capable of communication with an exhaust port 19 also provided through the wall of the cover 36. Radial port I4 is capable of communication with a passageway 89 which leads fromthe throttle valve through the different parts housed within the housing 34 to open into the rear end portion of a bore 8| provided Within the upper front end portion of the cap 35, which borehas slidably mounted therein an auxiliary valve 82 having a shank 83 extending longitudinallyfromthe cap 35 abovethefeed screw 3| and capable'of engagement by the back head 24 of the drill motor 29. This valve is urged and normally maintained in its foremostposition within the bore 8| by a compression. spring 84 interposed between the valve and the bottom of the bore 8|. Longitudinally spaced from the opening of the passageway 89 in the bore 8|, there is ,the opening of another passageway 85 which leads fromthe bore 8| into the plate 5| via the plate 59 and stator 52. In theplate 59 (Fig. 11)

there'is provided a port 86 afiording communication between the passageway 85 and a niche 81 formed in the side wall of the plate 59 adjacent thestator 52, which niche is capable of communication'with the rotor recess 63'shown in the substantiallyfive oclock position in Figs. 14 and 15 The port 89 extends beyond the niche 81 to finally open-through the side wall of the plate 59 adjacent the stator 52 and extends therefrom in the stator 52 to open inthe lower portion of the compartment 89 through a recess 88 (Fig. 15),

-Il'1 the stator 52 the passageway 85 is connected with theupper portion of the compartment 59 through a port '99'and a recess 89 (Fig. 15). In the plate 5|, the passagewayv85 is in communication with a niche 9| through a port 92 (Fig. 13) which niche 9| is capable of communication with the rotor recess 83 shown in the substantially elevenoclock position in Figs. 14 and 15.

Leading from the throttle valve 65 in the vertical plane'indicated. by line 88 in Fig. 2, there is a passageway 93 opening into a niche 94 (Fig. 113) formed on the face of the plate I 3 adjacent thethrottle 'valve 65.- From the niche 94 there is a'port 95 extending partway through the plate and partway through the stator 52 to end in a recess 96 (Fig. 14) opening into the upper end of the compartment 69. The port is also connected with a niche 91, (Fig. 13) through a port 98, which niche 94 is provided on the side wall of the plate 5| adjacent the stator 52 and is capable of connection with the rotor recess 63 located in the substantially one o'clock position in Figs. 14 and 15. Leading from the niche 94, there is another port 99 which extends in the stator 52 where it is connected with the lower end of the compartment 59 through a recess I99 (Fig. 14). From thestator 52 the port 99 continues into the plate 59 where it is connected with a niche |9| through a port I92 (Fig. 11), which niche is capable of communication with the rotor recess 63 in the substantially seven oclock position in Figs. 14 and 15.

Disposed at right angle with the lands 51 and 58 engaged by the rotor 55, there is provided through the wall of the stator 52 exhaust ports I94 opening into the partly circular groove 53 of the stator 52, which groove is in constant communication with the atmosphere through an exhaust port I95.

In the operation, when the throttle valve 65 is located as shown in Figs. 3 and 8, it will be understood that since the. port I4 is out of communication with the passageway 89 and the port II with the passageway 93, admission of the motive fluid through the feed motor 34 is prevented, thereby precluding feeding motion of the rock drill 29 relative to the shell 26. In this instance, the rock drill 29 is secured on-the shell against accidental movementrelative thereto due to the self-locking threads of the feed screw 3| and feed nut 29. Upon rotation of the throttle valve into the-position shown in Figs. 4 and 9,

motive fluid from the valve bore I3 (Fig. 9) will flow into the niche 94 through the passageway 93 and therefrom into the recesses 96 and I99 through the ports 95 andv 99 respectively, to act on the vanes 6| in the one and seven oclock position in Fig. 14 for imparting rotation to the rotor 58 in the clockwise direction. After these vanes have uncovered the exhaust ports I94, the motive fluid will exhaust into the annular groove 53 and therefrom to the atmosphere via theexhaust port I 95, thereby preventing back pressure on the vanes retarding the rotation of the.rotor 55. Concurrently, the vanes subjected to the action of the motive fluid in the compartments 69 and 59 through the recesses 96 and I09 will also be subjected to the action of the motive fluid admitted into the rotor slot 6| through the rotor recesses 63 which are in communication with the niches 91 and IN, the former being supplied with motive fluid through the port 98 communieating withrthe port 95 (Fig. 13) and the latter through the port I92 (Fig. 11) communicating with the niche 94 through the port 99 (Fig. 13) thereby causing the motive fluid to act on the lower end of the vanes for urging them against the inner wall of the rotor chamber 55.

During the rotation of the rotor 55 in the clockwise direction in Fig. 14, theshaft 54 secured to the rotor by the key 56will of course transmit rotation in the same direction to the pinion 44 and the gear wheels 45 in the other direction. The wheels 45 operatively engaging the'ring gear 41 will transmit rotation thereto in the same direction but at a materially reduced rate of speed, which rotation is finally transmitted to the feed screw 3| through the Oldham coupling 42. Due to the operative engagement of the screw with the feed nut 29, rotation of the feed screw 3| in this last direction will impart forward feeding motion to the rock drill 20 for maintaining the drill steel 22 in contact with the work.

Upon rotation of the throttle valve 65 in the position shown in Figs. 5 and 10, the motive fluid previously admitted into the rotor chamber 55 through the recesses 96 and I60 will now escape therefrom through the passages 95 and 99 respectively, the niche 94, the passageway 93, valve groove 78 and exhaust port 19, as shown in Fig. 10. Concurrently, motive fluid from the throttle valve bore 13 will be admitted into the bore 8| through the passageway 86. With the auxiliary valve 82 in the position shown in Fig. 2, motive fluid from the bore 8| will flow through the passageway 85 into the recess 89 (Fig. 15) through the port 90 and into the recess 88 through the port 86, thereby causing the motive fluid to act on the rotor vanes 62 in the eleven and five o'clock position in Fig. 15 for imparting rotation to the rotor 55 in a counterclockwise direction. Concurrently, from the passageway 85 motive fluid will also be admitted into the niche 9| through the port 92 (Fig. 13) and into the niche 81 (Fig. 11) through the port 86 for admitting motive fluid into the rotor slots 6| through the recesses 63, within which slots are located the vanes 62 acted upon by the motive fluid admitted into the compartments 60 and 56 through the recesses 88 and 69, thereby maintaining these vanes in fluid tight engagement with the inner wall of the rotor chamber 54. As the vanes uncover the exhaust ports I04, the motive fluid will exhaust from the rotor chamber into the semicircular groove 53 and therefrom to the atmosphere via the exhaust port I05.

Rotation of the rotor 55 in a counterclockwise direction in Figs. 14 and 15, will also be transmitted to the pinion 44 through the shaft 43, and from the pinion through the gear wheels 45 to the internal gear 4| in a clockwise direction in Fig. 12, thus resulting in a rotation of the feed screw for imparting rearward feeding motion to the rock drill 28. In this instance, as the rock drill approaches the end of the return or rearward stroke, the head 24 will engage the free end of the valve shank 83 causing the valve to close the passageway 85, thereby automatically shutting ofif the supply of the motive fluid to the passageway 85 and consequently to the rotor chamber 55 for preventing further operation of the feed motor 34.

Upon rotation of the throttle valve into the position shown in Figs. 4 and 9, the motive fluid previously admitted into the rotor chamber 55 through the recesses 88 and 89 will exhaust therefrom through the passageways 85 and 85, valve groove 15 and exhaust port I6, thereby enabling free rotary movement of the rotor 55 in a clockwise direction as hereinabove explained.

From the foregoing explanation, it will be understood that the fluid motor provided within the housing 34 is of the reversible rotary type equipped with a plurality of inlet ports for admitting motive fluid into the rotor chamber to act on at least two of the vanes 62 carried by the rotor 55, thereby resulting in a powerful rotary motor of simple and efficient construction. The gears transmission shown in Fig. 12 are calculated to materially reduce the rotary speed of the motor for transmitting rotation to the feed screw 3| at a greater rate of power than that of the feed motor, a feature which has been found important especially when removing or pulling stuck drill steel from the drilled hole, as well as maintaining the drill steel 22 in contact with the work. By providing the auxiliary valve 82, rearward motion of the drill motor is limited to prevent transmission of impacts by the drilling motor to the housing 54 of the feeding motor. Through the Oldham coupling 42, slight variation of alignment between the feed screw 3| and the gear 4| may take place without resulting in excessive binding or frictional resistance of the several parts of the mechanism.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. In a fluid actuated rotary motor of the reversible type, a hollow stator, a rotor within said stator, a plurality of vanes operatively carried by said rotor, a pair of diametrically opposed compartments between said stator and rotor of substantially crescent shape cross section, means including a throttle Valve for concurrently admitting motive fluid into two diametrically opposed end portions of said compartments and for exhausting motive fluid from the other two opposed end portions thereof for actuating said rotor by virtue of the action of the motive fluid on said vanes, said throttle valve being operable for reversing admission and exhaust of the motive fluid into and from said diametrically opposed end portions for selectively controlling the direction of rotation of said rotor, and an auxiliary valve capable of preventing admission of motive fluid into two diametrically opposed end portions of said compartments irrespective of said throttle valve.

2. In a fluid actuated rotary motor of the reversible type, a stator, a rotor within said stator, a pair of diametrically opposed compartments between said stator and rotor, radially movable vanes carried by said rotor engageable with the outer walls of said compartments, an inlet passage opening into one end of each compartment for concurrently admitting motive fluid to at least two of said blades to effect the rotation of said rotor, a venting passage opening into the other end of each compartment to prevent back pressure therein during said rotation, a rotatable throttle valve associated with said passages for selectively reversing the use thereof to control the direction of rotation of said rotor, a slidable auxiliary valve capable of preeluding admission of motive fluid into one end of each compartment irrespective of said throttle valve, and motive fluid exhausting means for each compartment intermediate the ends thereof.

WILLIAM A. SMITH, JR. 

